YOU FORGOT A GROUND WIRE
On 8/26/2015 1:07 AM, [email protected] wrote: > Hello, > > I have a BeagleBone Black with a "Serial Cape" > (http://www.logicsupply.com/eu-en/cbb-serial/). This cape supports > RS-485 which i'm interested in. Before i had this cape, i used a > RS-485-to-USB-converter. > > > My problem: > I try to read some data from an external device. It's very simple: The > request is just "/?!\r\n" and then i get the data. > > With the RS485-to-USB-Stick i used this serial port configuration > (with ser2net): > /dev/ttyUSB0 9600 7DATABITS EVEN 1STOPBIT > > With the cape i tried this configuration: > /dev/ttyO4 9600 7DATABITS EVEN 1STOPBIT > > Unfortunately this first try didn't work. I didn't get any response. I > also tried this configuration: > /dev/ttyO4 9600 7DATABITS EVEN 1STOPBIT RTSCTS > > I set the jumpers on the cape like this: > J8: RS485 > J7: UART4 RTS > > The RS485+ wire is connected to the RS485B port, and the RS485- wire > is connected to the RS485A port. > (https://docs.google.com/document/d/1sgurQ-7gLyn7g-Kg983NRM0aDkYEqHqy9dmrieX_RUM/edit > page7) > > To get a better overview i made a photo: > > <https://lh3.googleusercontent.com/-DGOBBHIo6sM/Vd1xuVsgc_I/AAAAAAAAAEE/JS4oAhPYoOk/s1600/IMG_20150826_091607_mod.jpg> > > > > At the bottom of the picture there is the RS485-to-USB converter. It > just has two ports which i used to connect the RS485 wires. > > I think the board itself should work, because if i execute "cat > /sys/devices/bone_capemgr.*/slots" i can see it. > > My question: > Do i do something wrong? Maybe someone else has used this cape with > RS485? I thought it should be almost as easy as with the USB converter? > > > Thank you for any help > > Best regards > Benj > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google > Groups "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send > an email to [email protected] > <mailto:[email protected]>. > For more options, visit https://groups.google.com/d/optout. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
